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BGP Set Commands
local-AS
no-advertise
no-export
none
Syntax of the "no" Form
The no form of this command removes the set community value:
no set community
Mode
Route‐map configuration:
Example
The following example configures the set community value in the context of configuring route map
1 and the neighbor send community value:
XSR(config)#ip access-list 37 permit 10.0.0.0 255.0.0.0
XSR(config)#route-map 1 permit 1
XSR(config-route-map)#match ip address 37
XSR(config-route-map)#set community 500:10
XSR(config-route-map)#exit
XSR(config)#route-map 1 permit 2
XSR(config-route-map)#set community none
XSR(config-route-map)#exit
XSR(config)#router bgp 100
XSR(config-router)#neighbor 192.168.1.1 remote-as 101
XSR(config-router)#neighbor 192.168.1.1 send-community
XSR(config-router)#neighbor 192.168.1.1 route-map 1 out
Route map 1 is applied to the outgoing BGP updates between this router and its peering neighbor
identified by IP address 192.168.1.1 in AS 101. The first instance of route map 1 matches the
destinations in the BGP updates against the criteria specified in ACL 37 (10.0.0.0/8). If there is not a
match, the second instance of route map 1 is invoked, which matches on all remaining routes and
removes any community attributes. This means that routes matching ACL 37 criteria will have a
community attribute set to 500:10, but all of the other routes advertised to 192.168.1.1 will not.
The BGP peer 192.168.1.1 will then have the option to apply a desired routing policy to all routes
arriving from this router with the community attribute set to 500:10.
set dampening
This command configures route flap dampening, a mechanism to combat network overhead
which arises from the proliferation of uncontrolled disconnecting/reconnecting networks.
With route dampening, you can address these problem routes as follows:
6-116 Configuring the Border Gateway Protocol
Established community which specifies that routes containing this value
should not be advertised to external BGP peers.
Established community which specifies that routes containing this value
should not be advertised to any other BGP peers (internal or external).
Established community which specifies that routes containing this value
should not be advertised outside a BGP confederation boundary.
Removes any existing communities.
XSR(config-route-map)#
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